The aim of our research is to determine the risk of bone disease in hypercalcuric kidney stone formers and their families by establishing an algorithm that takes into account bone mineral density (BMD), demographic characteristics, diet history, and urine chemistries, including markers of bone turnover. This algorithm will allow us to determine which hypercalcurics need clinical evaluation for osteoporosis and will form the basis of a disease management product. In the process of creating this algorithm, we will be the first to determine the prevalence of bone disease in hypercalcuric stone formers and their families and over time make some estimates of incidence rates. A longer-term goal of our research is to study the genetic underpinnings of osteoporosis and nephrolithiasis. PROPOSED COMMERCIAL APPLICATION: Litholink provides disease managment services for kidney stone patients. We hope to use the algorithm developed in this research to expand our services to include bone disease management in kidney stone forming patients and their families.